Weed eater engine conversion

Discussion in 'DIY Marinizing' started by Ward, Jun 2, 2003.

  1. wet-foot
    Joined: Sep 2003
    Posts: 176
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: canada

    wet-foot Senior Member

    A few things to consider, Use any prop that will bolt to the shaft. Use water proof grease in the flex shaft housing. Try convert the handle into the transom bracket. The handles are usually adjustable to slide up and down the shaft ....... keep this option as the biggest concern you will have once you make it work will be prop depth. If the prop runs too deep you will get a lot of cavitation ( no speed ) ..... shallow is what you want. You should be able to adjust the vertical height with the handle and the prop angle by tilting the engine. Also convert the exhaust with a tube that reaches under water ....... now that's quiet!!!!!! The only thing you can't really fix is the fact weedeater motors are meant to run at full throttle like chainsaws ...... but it will still work, just a little hard to control your speed. Good Luck - let us know how you make out.
     
  2. Guest

    Guest Guest

    Hey Tex! It isn't dumb. It's a great idea and it works. I had one but some miserable, oxygen-thieving waste of space needed it more than me. Apparently! I can't tell you anything about it of use to you other than it was direct drive. The shaft had been cut down to about two and a half feet and it was a Ryobi Scorpion which as you say is 30cc. It was so ingenious I fell in love with it even though I know nothing about motors. In fact I was surfing the net looking for something on my Evinrude Junior which I also know nothing about when I hit this site and decided to give it a go. I got a real kick when I saw your name cause we must be cousins. My name is Joe Ward but I ain't in Texas. I'm in Gladstone, Queensland, Australia. When I read your request for info on a weedeater outboard I felt I had to at least let you know you ain't dumb and in all likelihood are probably a genious. I thought I'd had the only one in existence and to find out there's another Ward out there in Texas who's trying to make one made me smile. If this ain't a billion to one shot coincidence then there ain't no such thing.Take care dude and don't give up. It works.
    Cousin Joe.
     
  3. fourwheelin415
    Joined: Oct 2003
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: wisconson

    fourwheelin415 New Member

    weedeater outboard

    hi me and my freind put together a weed eater boat motor with a idc weed eater motor and and a homlite shaft and the rod on the in side we only had to modify it slitly. Then we used a prop off a eska trowling motor and we constently said that it was going to gether to easy and when we got done and started the motor we relized that it was runing backwards. So if any one knows where i can get a counter clock wise prop cheap let me know.
     
  4. TopSpin80
    Joined: Oct 2003
    Posts: 6
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Galveston

    TopSpin80 Junior Member

    I would definately not go with a flex shaft. I have r/c weedeater boats and flex shaft's don't work. There is a huge torque load on a marine engine at all times no matter the hp. The flex shaft is designed for a weedeater application running in free air and only minimal torque, it will break all the time in a marine application.
     
  5. SailDesign
    Joined: Jan 2003
    Posts: 1,964
    Likes: 91, Points: 58, Legacy Rep: 650
    Location: Jamestown, RI, USA

    SailDesign Old Phart! Stay upwind..

    One of the early Herreshoff steam launches had a "bent" (his words) prop shaft. No word on whether it was successful or not, apart from the fact that no-one does it any more...
     
  6. fourwheelin415
    Joined: Oct 2003
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: wisconson

    fourwheelin415 New Member

    The weed eater/ out bouat me and my freind built works great we didnt finish the transome mount but it does push us along great in the boat we built. Its only an eight footer but it pretty good for our first one. Where going to start building a 10 footer the winter. Where going to put the weed eaters "3" in the middle of the boat witha straight shaft running out the bottom of the boat with the rudders on the back. We are just builting jon boats so far. But there my design and no one is helping us so i think thats good for a couple of 15 year olds. And that flez shaft works great for us so were going to stick with it and build a couple more motors to put in our new boat.

    Cody
     
  7. gonzo
    Joined: Aug 2002
    Posts: 13,964
    Likes: 489, Points: 93, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Where in Wisconsin are you? I teach boatbuilding in Milwaukee. Call me if you need any help.
     
  8. SailDesign
    Joined: Jan 2003
    Posts: 1,964
    Likes: 91, Points: 58, Legacy Rep: 650
    Location: Jamestown, RI, USA

    SailDesign Old Phart! Stay upwind..

    Gonzo - you're a good man. Thanks.
     
  9. fourwheelin415
    Joined: Oct 2003
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: wisconson

    fourwheelin415 New Member

    I was woundering if any one gould hook me up with a stearing unit and cable. I have a very tight buget and would like to make my boat a inboard. The only problems that ive been having is the stearing. I tryed cables but it didnt work at all. The rudder bairly move left and right. Olso i was wondering if any one had any extra smaller props lying around.

    Thanks, cody
     
  10. gonzo
    Joined: Aug 2002
    Posts: 13,964
    Likes: 489, Points: 93, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    Pulleys work if properly designed. I'll post a schematic tomorrow. Can you use a beat up propeller?
     
  11. fourwheelin415
    Joined: Oct 2003
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: wisconson

    fourwheelin415 New Member

    SURE, But ive slitly altered my plans. I am now going to make a few changes to my boat. I am going to combine it with a lawnmower and other scrap metal to make it a anphibious vehical, instead of having to push it on a dolly i made. And because my dad wants me to get rid of the mower. Ive got it planned out and have almost all of the nessesitys exept the scrape metal, which ill get this summer when i have some money. thanks. Ill send you some of my plans if i can get my scanner to work.


    Cody
     
  12. Joshua C.

    Joshua C. Guest

    inventor

    Hey man,
    Just built a boat around high performance weed wacker engines. uses two 25.4cc 2cycle gas engines(3.5 HP each) and mini jet drives (I ould only get 1/3 throttle and about 12 mph out of my old canoe before air was forced into the jets and they would cavitate, wrong hull shape). MANY other mods to be put on the web later as I am 4 days away from the maiden voyage/christaining.

    HINT to use an el cheapo gas engine you will need a clutched model (more torque ) and you will need to mount your engine in the boat through the hull and use a "stuffing tube filled with grease" or figure out a way to seal the shaft or the rotating flex shaft will draw water up the pipe and all over you and your boat/engine. So far as the prop is concerned I started out using a 2.9" RC boat prop (I think it was called a prather 275) and with a single 30cc john deere with a clutch I was able to go faster than paddling with 2 people and gear in the boat!!

    Belive me I have been wasting $ on this project for 3 years and KNOW what I am talking about!!! The el cheapo engine can be done if you follow my advice and for about $250 smackers using NEW equip. a good tuned/muffled pipe to keep the racket down will cost ya though.

    Feel free to contact me degreeoff1@yahoo.com

    good luck
     
  13. big_p
    Joined: Apr 2004
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: RI

    big_p New Member

    Hi!!!
    This is my first post. I was searching on google about a weed wacker outboard and found this! I'm glad to be here. This is right up my alley.

    I made one of those before. I still have some pictures that I'd like to put on here sometime. It was very simple. I found a small 2 bladed prop from a Cruise n' carry outboard at my local marine consignment shop (Wickford Marine Consignment, North Kingstown, RI) and a standard Weed Eater brand engine. It had a curved shaft. All I had to do was just bend the shaft a little more. It was not a big deal at all. I stuck it in my vice and bent it a few inches at a time in different places (so I wouldnt kink the cable inside). Mounting the propeller was the only hard part. I had to bore it out a little using a dremel. In the end I drilled a hole through the propeller and weed eater shaft, and stuck a cotter pin through it. for the mounting of the weed eater to the boat: I got the clamp assembly off an old 3.5 horsepower Eska that I bought on ebay. I had to put an adapter around the weed eater shaft, because it was much too small. I mounted a throttle cable that led to the tiller. I put it on my friend's 14' boat (that had a 25 on it) and I hit 2.5mph :D

    I am currently working on a 1.2hp Eska that I am putting on a 2hp Tecumseh engine on.
     
  14. Jack Jackson
    Joined: Apr 2004
    Posts: 1
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Houston, Tx

    Jack Jackson New Member

    I have seen this done with a Flexable shaft weed eater. I also know how to do it with a straight shaft hh=ook up. Both require a bearing mount next to the prop. If you are still interested, please e-mail me and tell me what type you have.
    Jack Jackson
    Houston, Tx
     

  15. Kurt

    Kurt Guest

    Unrelated question

    I am planning on turning a jon boat into a bass boat and i would like to have a center console with stearing. Is there any way you can get a hand controled 5 hp outboard motor and make it so that it can be controled through a stearing wheel? Is there a way to wire it so it can be controled through a stearing wheel? If any body can help please reply.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.